Generating a new address from Javascript

Is it possible to generate a new address from Javascript / JSON RPC? The only option to do this that I know of is the menu option in AlethZero. To clarify, I don't mean deleting all user data and automatically gaining a new address, I mean adding one so the node knows multiple addresses.

I know how to get the current addresses with web3.eth.accounts. I'm looking for something like web3.eth.newAccount().